Читать книгу American Red Cross Text-Book on Home Hygiene and Care of the Sick - American National Red Cross - Страница 29

—Amount and direction of light are physiologically important. Defects of the eyes, too prolonged use, and insufficient light are the commonest causes of eye strain. Most eye defects can be relieved by glasses. Children's eyes should be examined upon entering school, and as often afterward as the oculist advises. Prolonged use causes fatigue of the eyes, especially when the illumination is poor; within limits, the amount of light needed depends on the nature of the work. Light should come from the left side of right handed people; never from the front. Light reflected from snow, sand, glazed white paper of books, or other bright surfaces is fatiguing from its intensity, and from the unusual angle at which it enters the eyes. Too much light is harmful, and probably causes some of the effects, such as nausea and headache, commonly attributed to poor ventilation.

Almost all blindness is preventable, and blindness due to industrial accidents and processes is no exception to this rule. Surely no individual precautions or legal measures are too great in order to guard against this saddest of all physical defects.